ul {
    width: 500px;
    border: 1px solid;
    padding: 0;
    text-align: center;
    margin: auto;
    li {
        border: 1px solid;
        list-style: none;
        line-height: 30px;
        &:nth-child(2n) {
            background-color: aqua;
        }

        &:nth-child(2n-1) {
            background-color: pink;
        }
        &:hover {
            background-color: green;
            color: white;
        }
    }
}